Research Article| November 01, 1991 Relation of sediment load and flood-plain formation to climatic variability, Paria River drainage basin, Utah and Arizona JULIA B. GRAF; JULIA B. GRAF 1U.S. Geological Survey, Water Resources Division, 375 S. Euclid Tucson, Arizona 85719 Search for other works by this author on: GSW Google Scholar ROBERT H. WEBB; ROBERT H. WEBB 2U.S. Geological Survey, 1675 W. Anklam Road Tucson, Arizona 85745 Search for other works by this author on: GSW Google Scholar RICHARD HEREFORD RICHARD HEREFORD 3U.S Geological Survey, Geologic Division, 2255 North Gemini Drive, Flagstaff, Arizona 86001 Search for other works by this author on: GSW Google Scholar Author and Article Information JULIA B. GRAF 1U.S. Geological Survey, Water Resources Division, 375 S. Euclid Tucson, Arizona 85719 ROBERT H. WEBB 2U.S. Geological Survey, 1675 W. Anklam Road Tucson, Arizona 85745 RICHARD HEREFORD 3U.S Geological Survey, Geologic Division, 2255 North Gemini Drive, Flagstaff, Arizona 86001 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1991) 103 (11): 1405–1415. https://doi.org/10.1130/0016-7606(1991)103<1405:ROSLAF>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation JULIA B. GRAF, ROBERT H. WEBB, RICHARD HEREFORD; Relation of sediment load and flood-plain formation to climatic variability, Paria River drainage basin, Utah and Arizona. GSA Bulletin 1991;; 103 (11): 1405–1415. doi: https://doi.org/10.1130/0016-7606(1991)103<1405:ROSLAF>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Suspended-sediment load, flow volume, and flood characteristics of the Paria River were analyzed to determine their relation to climate and flood-plain alluviation between 1923 and 1986. Flood-plain alluviation began about 1940 at a time of decreasing magnitude and frequency of floods in winter, summer, and fall. No floods with stages high enough to inundate the flood plain have occurred since 1980, and thus no flood-plain alluviation has occurred since then. The decrease in magnitude and frequency of floods appears to have resulted from a decrease in frequency of large storms, particularly dissipating tropical cyclones, and not from a decrease in annual or seasonal precipitation.Suspended-sediment load is highest in summer and fall, whereas flow volume is highest in winter. Fall shows the greatest interannual variability in suspended-sediment load, flow volume, and flood size because climatic conditions are most variable in fall. The relation between sediment load and discharge apparently did not change within the period of sediment sampling (1949-1976), even though the channel elevation and width changed significantly. Annual suspended-sediment loads estimated for periods before and after 1949-1976 show that decrease in suspended-sediment load caused by floodplain alluviation in the Paria River and other tributaries could have been a significant part of the decrease of suspended-sediment load in the Colorado River in the early 1940s. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.